Anthocyanin Profile and Antioxidant Property of Anti-asthma Flowers of Cordyline terminalis (L.) Kunth (Agavaceae)

Cordyline terminalis flower is traditionally used to treat asthma and the purple color of the flower is suggestive of anthocyanins. The purpose of this study was to characterize and determine the antioxidant property of anthocyanins from C. terminalis purple flowers. Five anthocyanins, cyanidin 3,5-di-O-β-glucopyranoside (2.6 ± 0.2 mg/g fr. wt) (1), peonidin 3,5-di-O-β-glucopyranoside (2.8 ± 0.3 mg/g fr. wt) (2), cyanidin 3-O-β-(6″-O-E-p-caffeoylglucopyranoside)-5-O-β-glucopyranoside (3.2 ± 0.2 mg/g fr. wt) (3), cyanidin 3-O-β-(6″-O-E-p-coumaroylglucopyranoside)-5-O-β-glucopyranoside (6.2 ± 0.4 mg/g fr. wt) (4), and peonidin 3-O-β-(6″-O-E-p-coumaroylglucopyranoside)-5-O-β-glucopyranoside (9.8 ± 0.2 mg/g fr. wt) (5), were isolated from the flowers of C. terminalis by a combination of chromatographic techniques. Their structures were established by UV-visible, NMR, and ESI-MS. The extract exhibited appreciable antioxidant activity (IC50 ± SD = 13.1 ± 0.8 μg/mL) against quercetin (IC50 ± SD = 4.5 ± 0.4 μg/mL) compared to the individual anthocyanins (IC50 ± SD = 13.8 ± 0.5 to 16.4 ± 0.7 μg/mL) when measured using the 2,2-diphenyl-1-picryl-hydrazyl method. Cordyline terminalis flowers extract may be justified for use and standardization as herbal remedy for asthma.publishedVersio

The Cyanogenic Potential of Certain Cassava Varieties in Uganda and Their Fermentation-Based Detoxification

Cassava is the leading staple food in the developing world, providing an essential diet for about half a billion individuals. However, cassava contains significantly toxic compounds, the cyanogenic glycosides. Ingestion of such toxins in large quantities can lead to acute cyanide poisoning and may cause death in both humans and animals. Therefore, cassava may present a potential health risk to consumers. Information regarding the cyanogenic glycoside content is vital in averting health risks associated with cassava consumption. Accordingly, the seven most common local cultivars in Zombo district and six improved cultivars were grown and later characterized based on their cyanogenic potential. Additionally, the root tubers of Nyar-udota and Nyar-papoga were fermented to detoxify them from the cyanogens. The cyanogenic glycoside levels in the selected cultivars surpassed the critical value of 10 ppm established by the World Health Organization. The improved cassava had lower and moderately identical concentrations of HCN, unlike the local varieties. Cyanogenic contents were highest at 8-10 months. Fermentation led to substantial detoxification of the cyanogens, and the decrease varied with the fermentation period. In making choices for the cultivation and consumption of cassava, it is crucial to consider the cultivar, period of harvesting, and detoxification by fermentation

Purple anthocyanin colouration on lower (abaxial) leaf surface of Hemigraphis colorata (Acanthaceae)

The functional significance of anthocyanin colouration of lower (abaxial) leaf surfaces is not clear. Two anthocyanins, 5-O-methylcyanidin 3-O-(3″-(β-glucuronopyranosyl)-β-glucopyranoside) (1) and 5-O-methylcyanidin 3-O-β-glucopyranoside (2), were isolated from Hemigraphis colorata (Blume) (Acanthaceae) leaves with strong purple abaxial colouration (2.2 and 0.6 mg/g fr. wt., respectively). The glycosyl moiety of 1, the disaccharide 3″-(β-glucuronopyranosyl)-β-glucopyranoside), has previously been reported to occur only in a triterpenoid saponin, lindernioside A. The structural assignment of the aglycone of 1 and 2 is the first complete characterisation of a natural 7-hydroxy-5-methoxyanthocyanidin. Compared to nearly all naturally occurring anthocyanidins, the 5-O-methylation of this anthocyanidin limits the type of possible quinoidal forms of 1 and 2 to be those forms with keto-function in only their 7- and 4′-positions

Anthocyanin Profile and Antioxidant Property of Anti-asthma Flowers of Cordyline terminalis (L.) Kunth (Agavaceae)

Cordyline terminalis flower is traditionally used to treat asthma and the purple color of the flower is suggestive of anthocyanins. The purpose of this study was to characterize and determine the antioxidant property of anthocyanins from C. terminalis purple flowers. Five anthocyanins, cyanidin 3,5-di-O-β-glucopyranoside (2.6 ± 0.2 mg/g fr. wt) (1), peonidin 3,5-di-O-β-glucopyranoside (2.8 ± 0.3 mg/g fr. wt) (2), cyanidin 3-O-β-(6″-O-E-p-caffeoylglucopyranoside)-5-O-β-glucopyranoside (3.2 ± 0.2 mg/g fr. wt) (3), cyanidin 3-O-β-(6″-O-E-p-coumaroylglucopyranoside)-5-O-β-glucopyranoside (6.2 ± 0.4 mg/g fr. wt) (4), and peonidin 3-O-β-(6″-O-E-p-coumaroylglucopyranoside)-5-O-β-glucopyranoside (9.8 ± 0.2 mg/g fr. wt) (5), were isolated from the flowers of C. terminalis by a combination of chromatographic techniques. Their structures were established by UV-visible, NMR, and ESI-MS. The extract exhibited appreciable antioxidant activity (IC50 ± SD = 13.1 ± 0.8 μg/mL) against quercetin (IC50 ± SD = 4.5 ± 0.4 μg/mL) compared to the individual anthocyanins (IC50 ± SD = 13.8 ± 0.5 to 16.4 ± 0.7 μg/mL) when measured using the 2,2-diphenyl-1-picryl-hydrazyl method. Cordyline terminalis flowers extract may be justified for use and standardization as herbal remedy for asthma

Anthocyanin Profile and Antioxidant Activity of Edible Leaves of Dissotis brazzae Cogn (Melastomataceae)

Anthocyanins are colored bioactive phytochemicals in the class of flavonoids with high potential as dietary antioxidants. Demand for anthocyanins in functional food and nutraceutical industries has continued to increase over the past decades. However, sources of anthocyanins for commercial exploitation are currently limited. Tropical Africa and Uganda in particular, harbors many plant species with potential to serve as new sources of anthocyanins. In this study, the anthocyanin profile and antioxidant activity of edible leaves of Dissotis brazzae, a plant of tropical African origin, were investigated. Two known anthocyanins, (1) cyanidin 3-O-β-glucopyranoside (1.28±0.44 mg/g fr. wt.) and (2) cyanidin 3-O-α-rhamnopyranoside (1.89±0.42 mg/g fr. wt.), were isolated from D. brazzae purple leaves by a combination of chromatographic techniques. Their structures were elucidated mainly by homo- and heteronuclear NMR spectroscopy and online HPLC/UV-Vis spectroscopy. The isolated anthocyanins showed appreciable level of antioxidant activity against DPPH, with 1 (IC50=9.2±0.2 μg/ml) showing slightly higher antioxidant potency than 2 (IC50=14.0±0.6 μg/ml). However, quercetin (IC50=4.5±0.4 μg/ml) used as a reference showed a higher antioxidant activity than 1 and 2. The total anthocyanin content of D. brazzae leaves (317 mg/100g) was within the range (80 – 680 mg/100g) of anthocyanins content in most dietary sources. This is the first report of fully characterised anthocyanins from the genus Dissotis, which may be of taxonomic importance. A new dietary source of the rare cyanidin 3-O-α-rhamnopyranoside has been identified